Lesson number 1 about Turbos. (my lesson)

[Phoenix]

Well I started up the shogun with its turbo in it for the first time today.

Was fine , until I saw smoke and after 10 minutes it was ALOT of blue smoke.

Turns out its blowing oil in the compressor housing AND in the exhaust. And it turns out I need a bigger oil return line. I was using a 1/8 NPT ****** out of the pan - and nope its not enough.

Time to remove the pan and make a bigger hole.

 

[yamahaSHO]

Yeah, that's FAR too small. Might need more research before doing... Hopefully your seals are fine.

 

[92sho16]

-10an i believe is regarded as the minimum for a drain.

 

[91PDXmocha]

Are you using a oil restrictor on the turbo feed line ?

 

[turbosho]

at least 5/8 or 10an(same size).

 

[Off Road SHO]

92SHO16 and Turbo are correct, minimum of 5/8" and keep the amount of bends to a minimum. There shouldn't be any places in the return line where oil will pool up. I think a AN -2 or -3 is plenty big enough for a feed line on the pressure side.

Tom

 

[SHOtime2511]

+1 for -10AN
I'd go with -12 if you have the room.

 

[somedude_001]

it is a good idea to see if your turbo calls for a oil restrictor also. I think ball bearing units are the ones that normally call for this but best to check. I would not worry too much about the seals being bad. The relay on my electric oil pump from my turbo died a couple times when I was driving my turbo SHO and I would only notice when I had a massive smoke screen behind me when driving. fired the oil pump back up and after a few min of massive smoke cloud it would go away never to return.

My turbo was mounted very low so I used a tilton electric oil pump to scavenge oil from the turbo and return it to my oil pan. This is not the typical way to do things but when the pump was not running it would not allow oil to return from the turbo and it would back up go out the turbo seals.

 

[Phoenix]

Well I went with a 3/4 fitting to match the original GM outlet tube , which is quite big.

As far as oil restriction , the GM 6.5 goes up to 75 psi without any , so the turbo guy I spoke to said that I might be OK.

 

[somedude_001]

that pressure is only on the bearings anyway so you could probably double that number and it would not be a issue. The seals do not see oil pressure. The oil just splashes around a bit and drains out the bottom.

 

[rubydist]

clearly there is a seal somewhere that sees that pressure and keeps the oil from just blowing into the respective turbine wheels.

 

[firebat45]

For everyone saying 5/8" is the minimum, it depends on the turbo. Holset turbos usually take less oil than Garrett, and ball bearing take less than journal bearing. It stands to reason that less oil in needs less hose to drain out. 5/8" is the minimum for a journal Garrett, but I know that a journal Holset is just fine with 1/2". A ball bearing Garrett only needs 1/2" as well, and I'd wager that a ball bearing Holset would get by with 7/16" or even 3/8".

In any case, overkill doesn't hurt the drain. I'd go by the size of hole/fitting/****** on the actual turbo, no point going bigger than that.

 

[somedude_001]

clearly there is a seal somewhere that sees that pressure and keeps the oil from just blowing into the respective turbine wheels.

Clearly that seal is not designed to handle pressure or it would not leak because the drain is too small

 

[Off Road SHO]

More important than size is the back pressure that the oil encounters on its trip back to the pan. The path must always be downhill. A pool of oil in the drainback will cause back pressure.

Tom

 

[Phoenix]

Yup , already knew that , but thanks for pitching some more infos.

BTW that turbo is a borg/ihi , and with the size of the outlet , im guessing it eats alot of oil. And its not a bearing type.

 

[Shovert]

Make sure drain is above oil level. Maurice
Edit good info here. Pretty much take a person from basic to a better understanding
http://www.max-boost.co.uk/max-boost/lubrication.htm

 

[NEp8ntballer]

Make sure drain is above oil level. Maurice
Edit good info here. Pretty much take a person from basic to a better understanding
http://www.max-boost.co.uk/max-boost/lubrication.htm

or have a pump set up to drain the oil after shutting the car off.

 

[Sho Amo]

Hey guys, I think hes got it :wave:

 

[somedude_001]

sometimes this info will help someone searching in the future